A bot just defeated one of the world's best video gamers

An artificial intelligence program just annihilated its human competition at a world championship video game contest.

The AI win stunned the gaming community, because bots are generally considered inferior to expert human players.

This one from Open AI -- a nonprofit artificial intelligence research firm known mainly for its backing by serial entrepreneur Elon Musk, of Tesla(TSLA) and SpaceX fame -- is a different story, and possibly a cautionary one.

To test out some harmless uses for AI, one Open AI team taught a bot to play Dota 2.

Dota 2, for those unfamiliar, is an online multi-player battle game. It works kind of like a complex virtual version of capture the flag. Teams of players use powerful characters, called "heroes," to battle each other. The game ends when one team has taken down a structure, called an "Ancient," in the opposing team's home base.

OpenAI first ever to defeat world's best players in competitive eSports. Vastly more complex than traditional board games like chess & Go.

"Our bot is trained entirely through self play. It starts out completely random with no knowledge of the world, and simply plays against a copy of itself -- which means it always has an evenly matched opponent," Brockman said.

The bot kept playing until its skill level reached that of the world's best Dota 2 players, he added.

Then, Brockman said, it was time to put the bot to the test at The International, which is Dota 2's world championship. The tournament kicked off in Seattle on August 7, with a $10.7 million grand prize up for grabs.

On Friday, the bot entered a best-of-five series with Danil Ishutin, a professional Dota 2 player from Ukraine who goes by the name Dendi. Because this was a side attraction, the bot wasn't eligible for prize money.

(Dota 2 games are typically played between teams of five, but the organizers of The International decided to switch it up for the bot's match.)

Before the battle kicked off, Dendi greeted the screaming crowd at Seattle Center's Keyarena, where the competition was hosted, wearing a hooded white robe and playfully boxing the air.

Moments later, Open AI's bot was introduced as a pizza-box-sized robot draped in a silky black robe. It was flanked by burly bodyguards wearing all black, who proceeded to hook up the bot to a computer.

This isn't the first time a bot has made waves in the gaming world. Earlier this year, an AI built by Microsoft beat every level of the Ms. Pac-Man game -- something no human player has ever achieved.

Microsoft(MSFT, Tech30) also played a role in the bot's Dota 2 win on Friday. Musk thanked the company via Twitter for allowing Open AI to use the Microsoft Azure cloud computing platform to develop the bot.

Would like to express our appreciation to Microsoft for use of their Azure cloud computing platform. This required massive processing power.